If I were to buy a laptop in 2012 it would be one of these (in the following order):
Spec wise I guess you're supposed to look for Core i5/i7 processors with 256GB SSD hard drives (I'd want 512GB) and 4 to 8GB of memory and 6-7 hours of battery life. SD card slot, back lit keyboards, high res screens, a couple USB slots pretty much rounds things out. Might want to wait for Ivy Bridge processors, "retina display" for the MacBook as well as Mac OS X Mountain Lion or Windows 8 due out later this year.
For tablets, there's really only the iPad, no point in getting anything else at the moment unless you're a developer or want a tablet to just watch movies. For smart phones, either the iPhone 4S or the Samsung Galaxy Nexus and probably the next generation of both, due out later this year, is the safer bet.
My current setup (and will be through 2012 and a good part of 2013/2014) is a 13" MacBook Pro from a few years ago and a Nexus S that I upgraded with a better battery that can last me a day or two between charges. And no tablets yet.